Project Summary This grant supports a project to generate and characterize Xenopus mutants in key genes related to human disease, establish a new Xenopus Mutant Resource, develop new transgenic lines for genome editing and establish efficient site-specific integration. The long-term goals of the studies are to generate new models of human disease that will provide useful resources for the biomedical research community. The proposed studies will use CRISPR-Cas gene editing to create precise models of human disease in the amphibian Xenopus. The current studies are focused on developing Xenopus models of many different diseases for the entire Xenopus community, and each mutant will be developed in close coordination with individual researchers. There are four main aims to this proposal. First, we propose to collaborate with Xenopus researchers to characterize existing mutants (over 116) that were developed over the last four years. The mutants cover a wide range of topics that require varied expertise that can only be obtained through interactions with other researchers. Second, we propose to generate new mutants using CRISPR-Cas as requested by researchers. As the national stock center for Xenopus, we have the proven expertise to breed and maintain these mutants. Third, we will generate new transgenic lines that will be used for genome editing. These new lines will allow for more tissue-specific expression of Cas9. Fourth, we propose to develop homology directed repair for more efficient generation of site-specific integration of exogenous DNA. All of these aims will help enhance the utilization of CRISPR-Cas gene editing methods in the Xenopus model system.